Ground-detector



(No Model.)

O. H. MAGLOSKIB.

GROUND DETECTOR.

No. 428,050. Patented May 13, 1890.

Wfli E5555 fill-M A. w TMPHL J LL UNITED STATES PATENT OFFICE.

CHARLES H. MACLOSKIE, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

GROUND-DETECTOR.

SPECIFICATION forming part of Letters Patent No. 428,050, dated May 13, 1890.

Application filed August 31, 1889. Serial No. 322,625. (No model.)

To all whom it may concern.-

Be itknown that I, CHARLES H. MAcLosKIE, a citizen of the United States, residing at Allegheny, in the county of Allegheny, State of Pennsylvania, have invented certain new and useful Improvements in Ground-Detectors for Electric Systems, of which the following is a specification.

My invention relates to apparatus for indi- Io eating and detecting faults or grounds upon an electric-distrilo'ution system, especially an electric railway, in which the conductors are exposed for contact and inclosed in a slotted conduit beneath the roadway, where from the proximity of the earth and'a large amount of metal grounds are likely to occur.

My invention consists in providing at the central station an artificial ground-connection, including a resistance and a circuit-in- 2o terrupter of any well-known description, by which an irregular current by a branch from the main supply-current is sent over the line to the grounded point and thence returns to the artificial ground at the central station.

2 5 A telephone with an indicating-coil is then passed along the line in proximity to the conductor and the location of the ground detected by listening to the induction from the irregular current upon the line.

0 My invention also includes other features,

as enumerated in the claims hereinafter made.

My invention is illustrated in the accompanying drawing, wherein B represents the main generator; A and C, the two line-con- 5 ductors, respectively. The line A is shown with a fault at G, and will be hereinafter designated as a temporarilygrounded conductor.

D and E are motors on the line connected 40 with the conductors A and C. At the central station a branch extends from the conductor C alternately to the other conductor and the ground when the'apparatus is put in operation by closing switch H. A set of lamps K is always included in the branch F, and a second set of lamps is also included in the said branch line, the second set being either the group K or the group K according as the connection is to the opposite conductor or to the ground.

L is a magnet for interrupting the circuit on the principle of the ordinary make-audbreak device, although any other means may be employed for producing irregularity in the circuit sufficient to cause induction in the 5 5 telephone-coil.

M and N are two groups of lamps arranged in series in what I term a ground indicatorcircuit, connecting the line-wires, each group corresponding to the normal potential of the main line, and O is an intermediate switch by which either one or both of the two groups may be connected to the ground.

P represents an induction-coil adapted to i be passed along in proximity to either of the main conductors and produce in telephoneR a sound corresponding to the interruption of the circuit by the rheotome at the central station.

The operation of the apparatus is described as follows: The two groups of lights M and N are both normally connected to the ground by switch O. Suppose one of the main conductors, as A, becomes temporarily grounded by an accident, as indicated by the dotted lines at G. This will immediately short-circuit the group of lights M, so that, whereas before there was little or no light given out'by the lamps, (their total resistance being too great for the potential of the line,) after the ground G is established the lamps N will come up to their normal brilliancy and will at once indicate that the conductor A is grounded. A bell may also be included with the lamps N, if necessary, to give an alarm. In a similar manner, if the conductor C becomes grounded, the lamps M will become bright and give an indication to the operator. The operator will then throw the switch H to one side or the other, according to the conductor which is grounded, the position which is shown in the drawing being that corresponding to a groundon conductor A. There will then be a circuit from conductor C through lamps K, through the armature of L, through the coil of L, through the lamps K, to conductor A. This will cause the magnet to attract its armature until it comes in contact with the back-stop, and the circuit will be from conductor 0 to lamps K, to the armature, 10o

to lamps 1' to the ground, thence to the fault on conductor A, and by the conductor A back to the generator. The magnet Ii being thus cut out,its armature will be releasedand the first circuit restored. There will thus be kept up a vibration of the armature, causing an inten rupted circuit to be constantly sent along eonductor A to the ground. As there are always four lamps in series in this circuit corresponding to the normal potential of the line,there will be practically no spark at the contacts, as in no case will there be more current in this circuit than what is permitted by the resistance of the lamps. Of course anyother resistance than the lamps may be employed which will always correspond to the potential of the main generator and preventshort circuits and arcs at the rheotome. \Vhile the interrupted current is passing over conductor A, the coil P is passed along the line, the operator listening in the telephone. He will constantly hear the induction until he reaches the point G, where the ground is located. The sound in the telephone will then cease, and he will know that he has reached the fault. The fault being thus located, it can be at once repaired. By my invention I am enabled to at once locate a ground without any interference with the working of the road, for the ground-indicator will first give notice of the occurrence of a ground upon either line-conductor, and then by shifting the switch ll so that the ground-detector circuit is supplied with current from the generator the exact location of the fault can be discovered. The motors meanwhile will continue to operate so long as there is but one grounded conductor.

The arrangements of the lamps M and N for indicating a ground upon one conductor or the other I do not claim as my invention, nor do I claim, broadly, the method of. deducting a ground by means of an induced current.

lVhat I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination, with a temporarilygrounded conductor in an electric-distribution system, of a generator having its poles connected with the cond uctor and the ground, respectively, a cireuit-interrupter for interrupting the circuit of the generator, and an induction-coil with an indicator adapted to be passed along the said conductor to locate the position of the temporary ground.

2. The combination, with a two-wire electric-distribution system, of a main supply-generator, a grouml-detector circuit adapted to be supplied with an irregular current from the said generator, and comprising a temporarily-grounded line-conductor and an artificial ground, a switch for cutting the said ground-detectorcircuitinto and out of circuitwith the generator, and an induction-coil with an indicator adapted to be passed along the line-conductor for locating the position of the temporary ground, as described.

3. The combination, with a two-wire distribution system, of a main supply-generator, an artificial ground-connection, a circuitin terruptcr for interrupting the circuit passed through said ground-connection, and a switch for cutting the ground-connection into and out of circuit with the generator, substantially as described.

4. The combination, in an eleetric-distrilmtion system, of a main supply-generator, a line-conductor having a temporary ground, an artificial ground in circuit with said generator, a resistance and a circuit-interrupter in said artificial ground, and an inductioncoil adapted to be passed along the said conductor to locate the position of the temporary ground.

5. The combination, in an electric-distribution system, of a main generator, a line-conductor having a temporary ground, an artificial ground, and an interrupter connecting the faultless conductor alternately with the faulty conductor and the artificial ground.

(3. The combination, in an electric-distribution system, of a main generator, two insulated liue'conductors, an artificial ground, an interrupter adapted to make an irregular current in said artificial ground,and a switch for placing either of said conductors in connection with the said interrupter and artificial ground.

7. In an electric-distribution system, the combination, with the main supply-generator, of two insulated line-conductors, an artificial groulid-connection having a lamp K, a loop-circuit including the lamps K and K, with the magnet L, and a switch II, for placing the two line-conductors alternately in connection with the terminals of the loop-circuit, respectively.

S. The combination, in an electric-distribution system, of a groulid-indicator showing a temporary ground upon one of two line-conductors, and a ground-detector for locating the exact position of said temporary ground, consisting of a generator adapted to give an irregular current upon the faulty conductor and an induction coil with an indicator adapted to be passed along the said line-conductor to locate the fault.

9. The combination, in an electric-distribution system, of a main generator, a line-conductor having a temporaryground, a branch circuit from the faultless conductor having lamps or an equivalentresistance corresponi'ling to a part of the main potential, and a rheotome connecting said branch alternately to the opposite conductor and to the ground through a lamp or equivalent resistance corresponding to the supplementary part of the main potential.

Signed this 22d day of April, 188.).

OIIAS. II. MAOLOSKIE.

\Vitnesses:

WM. 0. KELLY, FRANK. NUSBAUM. 

